Iron Flat Head Pins, Nickel Free, Platinum ColorSize: about 1. 6cm~5. 0cm, 0.7mm thick(21 Gauge), Head: 2mmA jewelry-maker's staple, Flat Head Pins allow you to make earrings, pendants, links and drop embellishments faster than lightning. Caused by the property of material, pins may be bent but that won't impair their use.